Electronic device and electronic apparatus

ABSTRACT

An electronic device includes a semiconductor device and a wiring substrate having a wiring pattern. The semiconductor device includes: a semiconductor chip having an electrode; a convex-shaped resin protrusion provided on a surface of the semiconductor chip, the surface having the electrode; and wiring having a plurality of electrical coupling sections which are aligned on the resin protrusion and electrically coupled to the electrode. The semiconductor device is mounted to the wiring substrate so that the electrical coupling sections and the wiring pattern are brought into contact and electrically coupled with each other. The plurality of electrical coupling sections brought into contact with the wiring pattern include curved or bent shapes projecting in a longitudinal direction of the resin protrusion.

BACKGROUND

1. Technical Field

The present invention relates to an electronic device having asemiconductor device mounted to a wiring substrate and an electronicapparatus using the electronic device.

2. Related Art

Technologies for mounting electronic components such as semiconductorintegrated circuits (ICs) are used for circuit boards and liquid crystaldevices mounted to various types of electronic apparatuses. For example,an IC chip for driving liquid crystal is mounted as a semiconductordevice on a liquid crystal display to drive the liquid crystal panel.The IC chip may be mounted directly on a glass substrate whichconstitutes the liquid crystal panel or on a flexible printed circuit(FPC) which is mounted on the liquid crystal panel. The glass substrateand the FPC are examples of a wiring substrate. The mounting structureof the former is called a chip-on-glass (COG) structure, and themounting structure of the latter is called a chip-on-FPC (COF)structure.

In a process of mounting the IC chip that drives liquid crystal of theliquid crystal display having the COG structure, an IC chip 1021 isdisposed above a glass substrate 1011, with reference to FIG. 12A.Interposed between the IC chip 1021 and the glass substrate 1011 is ananisotropic conductive film (ACF) 1222 containing conductive particles1222 a dispersed in a thermoset resin 1222 b. Both the IC chip 1021 andthe glass substrate 1011 are then heated and pressured, with theconductive particles 1222 a therebetween, so as to bring bump electrodes1021B, 1021B of the IC chip 1021 into an electrical contact state on thealignment sections of electrode terminals 1011 bx, 1011 dx on the glasssubstrate 1011. The contact state is to be maintained by the curedthermoset resin 1222 b.

Generally, in order to improve reliability of the conductive connectionbetween the bump electrodes 1021B and the electrode terminals 1011 bx,1011 dx, it is necessary to fix the relative position of the IC chip1021 to the glass substrate 1011 in a state that the conductiveparticles 1222 a between them are elastically deformed. This is becauseto maintain the state of electrical contact with the interposedconductive particles 1222 a even if the thermoset resin 1222 b isthermally expanded due to temperature changes.

However, it is extremely difficult to obtain a predetermined amount ofelastic deformation of the conductive particles 1222 a because of theirminuteness.

Therefore, with reference to FIG. 12B, a technology for composing a bumpelectrode 1010 is proposed (e.g., see JP-A-2-272737), in which a resinprotrusion 1012 is provided above an active surface of the IC chip 1021,and a conductive film 1020 is provided above the surface of this resinprotrusion 1012. In this case, an insulating film 1026 is provided inadvance on the surface of a pad 1024 of the IC chip 1021, and a portionof the insulating film 1026 is made to open so as to provide a couplingsection 1022 to the pad 1024. Then, the conductive film 1020 of the bumpelectrode 1010 is extended to the coupling section 1022 so that the bumpelectrode 1010 performs as an electrode terminal of the IC chip 1201.

By pressing the bump electrode 1010 to a terminal of the glass substrate1011, the resin protrusion 1012 constituting the bump electrode 1010 iselastically deformed. Because the resin protrusion 1012 constituting thebump electrode 1010 is sufficiently larger than the conductive particles1222 a contained in the ACF, a predetermined amount of elasticdeformation can be obtained. In this state, the IC chip 1021 is fixed tothe glass substrate 1011 using the thermoset resin 1222 b, so that itbecomes possible to maintain the electrical contact state brought by theinterposed conductive particles 1222 a even if the thermoset resin 1222b is thermally expanded due to temperature changes.

However, because the glass substrate 1011, resin protrusion 1012,conductive film 1020, and thermoset resin 1222 b that constitute anelectrical contact section made conductive by the bump electrode 1010have different thermal expansion coefficients, the amount of deformationin each constituent by application of heat varies. Particularly, if theresin protrusion 1012 is convex-shaped, and if the conductive film 1020is aligned in plurality on the surface of the resin protrusion 1012, theamount of deformation increases near end portions of the resinprotrusion 1012 in a longitudinal direction due to the thermalexpansion. With the increase in the deformation amount of the resinprotrusion 1012, the variation in the deformation amount of eachconstituent increases, thereby possibly leading to deterioration of theelectrical contact state and to conductive disconnection. In this case,the possibility of conductive disconnection between the IC chip 1021 andthe glass substrate 1011 is a problem. Therefore, conductive connectionthat can withstand temperature changes is required, and this is atechnology required for the electronic devices.

SUMMARY

An advantage of the invention is to provide an electronic device thatwithstand temperature changes and maintain stable electric contact.

According to an aspect of the invention, an electronic device includes:a semiconductor device including a semiconductor chip having anelectrode; a convex-shaped resin protrusion provided on a surface of thesemiconductor chip, the surface having the electrode; and wiring havinga plurality of electrical coupling sections which are aligned on theresin protrusion and electrically coupled to the electrode, and a wiringsubstrate containing a wiring pattern, in that: the semiconductor deviceis mounted to the wiring substrate so that the electrical couplingsections and the wiring pattern are brought into contact andelectrically coupled with each other, and the plurality of electricalcoupling sections brought into contact with the wiring pattern includecurved or bent shapes projecting in a longitudinal direction of theresin protrusion.

In this case, the plurality of electrical coupling sections brought intocontact with the wiring pattern include curved or bent shapes thatproject in the longitudinal direction of the resin protrusion. Becauseof these curved or bent shapes, the length of sides constituting each ofthe plurality of electric coupling sections that have been brought intocontact with the wiring pattern may increase. This may increase anelectrical contact area, as compared to a straight-lined shape that isnot curved or bent. Therefore, despite the variation in the thermalexpansion of the wiring substrate, resin protrusion, and the like thatconstitute the electronic device, the electrical coupling sections maymaintain and prevent deterioration of a good electrical contact state.It is therefore possible to provide an electronic device that canwithstand temperature changes and maintain stable electric contact.

It is preferable that, in the electronic device, the plurality ofelectrical coupling sections brought into contact with the wiringpattern be provided such that a first length from an end thereof in awidth direction of the resin protrusion to a hypothetical center line ofthe resin protrusion in the longitudinal direction is longer than asecond length from a center thereof in the width direction of the resinprotrusion to the hypothetical center line.

It is preferable that, in the electronic device, the plurality ofelectrical coupling sections in contact with the wiring pattern beprovided such that the first length from the end thereof in the widthdirection of the resin protrusion to the hypothetical center line of theresin protrusion in the longitudinal direction is shorter than thesecond length from the center thereof in the width direction of theresin protrusion to the hypothetical center line.

In these cases, the plurality of electrical coupling sections broughtinto contact with the wiring pattern are provided such that the lengthfrom its end in the width direction of the resin protrusion to thehypothetical center line of the resin protrusion in the longitudinaldirection is longer or shorter than (is different from) the length fromits center in the width direction of the resin protrusion to thehypothetical center line. Thus, the plurality of electrical couplingsections brought into contact with the wiring pattern have shapesprojecting in the longitudinal direction of the resin protrusion.Because of this projection, the length of sides constituting each of theplurality of electric coupling sections that have been brought intocontact with the wiring pattern increases. This may increase theelectrical contact area, as compared to the straight-lined shape with nosuch projection. As a result, despite the variation in the thermalexpansion of the wiring substrate, resin protrusion, and the like thatconstitute the electronic device, the electrical coupling sections maymaintain and prevent deterioration of a good electrical contact state.It is therefore possible to provide the electronic device that canwithstand temperature changes and maintain the stable electric contact.

It is preferable that, in the electronic device, the plurality ofelectrical coupling sections brought into contact with the wiringpattern be provided such that a difference between the first length fromthe end thereof in the width direction of the resin protrusion to thehypothetical center line in the longitudinal direction and the secondlength from the center thereof in the width direction of the resinprotrusion to the hypothetical center line is larger at both endportions of the resin protrusion in the longitudinal direction than at acentral portion of the same.

In this case, it is possible to increase the contact area of each of theelectrical coupling sections located near the end portions of theconvex-shaped resin protrusion in the longitudinal direction, since thedeformation of the resin protrusion due to the thermal expansion ismaximized at the end portions. As a result, even if the temperaturechanges occur, it is possible to maintain good electrical contactbetween the wiring substrate and the electrical coupling sectionslocated near the end portions of the resin protrusion in thelongitudinal direction.

It is preferable that, in the electronic device, the plurality ofelectrical coupling sections brought into contact with the wiringpattern be provided such that the difference between the first lengthfrom the end thereof in the width direction of the resin protrusion tothe hypothetical center line of the resin protrusion in the longitudinaldirection and the second length from the center thereof in the widthdirection of the resin protrusion to the hypothetical center lineincreases gradually from the central portion of the resin protrusion inthe longitudinal direction toward the both end portions of the same.

In this case, as the deformation of the convex-shaped resin protrusiondue to thermal expansion gradually increases toward the end portions ofthe resin protrusion in the longitudinal direction, the contact area ofthe electrical coupling section in contact with the wiring pattern maygradually increase. As a result, even if the temperature changes occur,it is possible to maintain good electrical contact between theelectrical coupling sections and the wiring substrate.

According to another aspect of the invention, an electronic apparatusincludes: the electronic device, and a control section having a functionto at least operate a component including the electronic device.

In this case, it is possible to maintain and prevent deterioration of agood electrical contact state of the wiring substrate, resin protrusion,and the like that constitute the electronic device, even if theirthermal expansion varies due to the temperature changes. It is thereforepossible to provide the electronic device that maintains higherreliability.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a schematic, perspective diagram to explain a liquid crystaldevice which is an electronic device.

FIG. 2 is a sectional diagram of a semiconductor device taken on A-A ofFIG. 1.

FIGS. 3A through 3C are schematic diagrams to explain the semiconductordevice.

FIGS. 4A through 4C are schematic diagrams to explain a method formanufacturing the semiconductor device.

FIGS. 5A through 5D are schematic diagrams to explain the method formanufacturing the semiconductor device.

FIGS. 6A and 6B are schematic diagrams to explain an example of aprocess of providing wiring.

FIGS. 7A through 7D are schematic diagrams to explain a process ofmounting the semiconductor device and a wiring substrate.

FIG. 8 is a plan diagram of electrical coupling sections that have beenpressed, as shown from P-P of FIG. 7D.

FIGS. 9A through 9C are diagrams showing applications of the shape ofthe electrical coupling section.

FIG. 10 is a diagram showing an example of an electronic apparatus.

FIG. 11 is a diagram showing an example of the electronic apparatus.

FIGS. 12A and 12B are sectional diagrams to explain a liquid crystaldisplay as an electronic device of a related art

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Embodiments of the invention will now be described with reference to thedrawings, using an electrooptical device as an example of the electronicdevice.

FIG. 1 is a pattern diagram showing a liquid crystal device which is oneembodiment of the electrooptical device. A liquid crystal display 100shown in the drawing includes: a liquid crystal panel 110; and asemiconductor device 1 containing a semiconductor chip 10 for drivingliquid crystal 10 (hereunder referred to as semiconductor chip 10). Ifnecessary, incidental members such as a polarizing plate, a reflectingsheet, and a backlight (not shown) may be provided.

Structure of Electrooptical Device

The liquid crystal panel 110 as a wiring substrate includes a basesubstrate 42 and a substrate 112 made of e.g. glass or plastic. The basesubstrate 42 and the substrate 112 are arranged opposite from each otherand attached to each other with e.g. a seal material (not shown). Filledbetween the base substrate 42 and the substrate 112 is liquid crystal(not shown) as an electrooptical material. An electrode 111 a composedof a transparent electric conductor such as indium tin oxide (ITO) isprovided on an inner surface of the base substrate 42. An electrode 112a is provided on an inner surface of the substrate 112, opposite fromthe electrode 111 a. The electrode 111 a and the electrode 112 a aredisposed perpendicular to each other. The electrodes 111 a and 112 a aredrawn to a substrate projection 111T, and electrode terminals 111 bx(wiring pattern 44) and electrode terminals 111 cx (wiring pattern 44)are provided at an end of this substrate projection 111T. Provided nearan edge of the substrate projection 111T is an input wiring 111 d. Alsoprovided at an inner end of the substrate projection 111T are terminals111 dx (wiring pattern 44).

Mounted above the substrate projection 111T is the semiconductor device1, with an adhesive material made of an uncured (state of stage A) or ahalf-cured (state of stage B) thermoset resin interposed therebetween.The semiconductor device 1 includes, for example, the semiconductor chip10, electrical coupling sections 32, and resin protrusions 20 which willbe described hereafter. Provided on a lower surface of the semiconductorchip 10 are the plurality of electrical coupling sections 32, each ofwhich is conductively connected to the terminals 111 bx, 111 cx, 111 dx(wiring pattern 44) on the substrate projection 111T.

A flexible wiring substrate 123 is mounted above input terminals 111 dyprovided at an outer end of the input wiring 111 d, with an anisotropicconductive film 124 interposed therebetween. The input terminals 111 dyis conductively connected to respective wires (not shown) provided onthe flexible wiring substrate 123. Then, a control signal, a videosignal, a power potential, and the like are supplied from an externalsection to the input terminals 111 dy via the flexible wiring substrate123. A drive signal for driving liquid crystal is then generated at thesemiconductor device 1 and supplied to the liquid crystal panel 110.

According to the liquid crystal display 100 of the embodiment having thestructure as described, upon application of a suitable voltage betweenthe electrodes 111 a and 112 a via the semiconductor device 1, itbecomes possible to reorient the liquid crystal of pixel portions, inwhich both the electrodes 111 a and 112 a are arranged opposite fromeach other, to modulate light and to thereby provide a desired image ona display region having pixels aligned in the liquid crystal panel 110.

FIG. 2 is sectional diagram of a side surface of FIG. 1 taken on an A-Aline to explain the mounting structure of the semiconductor device 1 ofthe liquid crystal display 100. Provided on an active surface (lowersurface in the drawing) of the semiconductor chip 10 are: theconvex-shaped resin protrusion 20 as a terminal of the side adjacent tothe semiconductor, and the plurality of electrical coupling sections 32provided on the surface of the resin protrusion 20.

The tips of the coupling sections 32 are pressure-welded and thuselectrically coupled directly to the terminals 111 bx, 111 dx of thebase substrate 42. The periphery of the electrical contact portionbetween the coupling sections 32 and the terminals 111 bx, 111 dx isfilled with an adhesive 50 made by curing an adhesive agent such as thethermoset resin.

Structure of Semiconductor Device 1

The structure of the semiconductor device 1 according to the embodimentwill now be described. FIGS. 3A through 3C are diagrams to explain thesemiconductor device 1.

Referring to FIGS. 3A through 3C, the semiconductor device 1 includesthe semiconductor chip 10 having electrodes 12 provided thereon. Thesemiconductor chip 10 may be a silicon chip, for example. The externalconfiguration of a surface 15 of the semiconductor chip 10, the surfacehaving the electrodes 12, is rectangular (rectangle or square). Thesemiconductor chip 10 includes an integrated circuit 14. Components ofthe integrated circuit 14 may be, but not limited to, active elementssuch as transistors and passive elements such as resistors, coils, andcondensers.

Referring to FIGS. 3A and 3C, the semiconductor chip 10 includes theelectrodes 12. The electrodes 12 are made of metal such as aluminum (Al)or copper (Cu). The electrodes 12 may be electrically coupled to aninternal section of the semiconductor chip 10. The electrodes 12 may beelectrically coupled to the integrated circuit 14. Conductors(conductive pads) not electrically coupled to the integrated circuit 14may also be referred to as the electrodes 12. The electrodes 12 may be apart of internal wiring of the semiconductor chip 10. In such a case,the electrodes 12 may be the part of the internal wiring of thesemiconductor chip 12 that is used for electrical coupling to theexternal section. Also, a cap layer such as TiN or Ni may be provided onthe surfaces of the electrodes 12.

With reference to FIG. 3C, the semiconductor chip 10 may contain apassivation film 16. The passivation film 16 is provided such that itexposes the electrodes 12. The passivation film 16 may have openings toexpose the electrodes 12. The passivation film 16 may be an inorganicinsulating film such as SiO₂ or SiN or an organic insulating film suchas polyimide resin, for example.

With reference to FIGS. 3A to 3C, the semiconductor device 1 accordingto the embodiment includes the resin protrusions 20. The resinprotrusions 20 are provided above the surface 15 of the semiconductorchip 10. Referring to FIG. 3C, the resin protrusions 20 may be providedon the passivation film 16.

The shape of each resin protrusion 20 is not limited to a particularshape. If the external configuration of the surface 15 is rectangular,the resin protrusion 20 may take a shape that extends parallel to anyside of the surface 15. For example, if the external configuration ofthe surface 15 is rectangular, the resin protrusion 20 may take a shape(convex shape) extending along a long side of the rectangle (see FIG.3A). In this case, the resin protrusion 20 may be arranged in a regionnear this long side. Then, the plurality of electrical coupling sections32 are disposed on one resin protrusion 20. Alternatively, the resinprotrusion 20 may be circular in top view. In this case, the resinprotrusion 20 may be half spherical. In this case, only one electricalcoupling section 32 may be disposed on one resin protrusion 20.

The material for the resin protrusion 20 is not limited to anyparticular material and may be any known material. For example, theresin protrusion 20 may be made of a resin such as polyimide resin,silicone-modified polyimide resin, epoxy resin, silicone-modified epoxyresin, acrylic resin, phenol resin, silicone resin, modified polyimideresin, benzocyclobutene (BCB), or polybenzoxazole (PBO).

The semiconductor device 1 of the embodiment includes wiring 30, withreference to FIGS. 3A through 3C. The wiring 30 is electrically coupledto the electrodes 12. The wiring 30 may be provided so as to come incontact with the passivation film 16. The wiring 30 may extend beyondthe resin protrusion 20 and reach over to the passivation film 16. Thatis, the wiring 30 may come in contact with the passivation film 16 (thesurface 15) at both sides of the resin protrusion 20.

Referring to FIGS. 3A through 3C, the wiring 30 includes the electricalcoupling sections 32. The coupling sections 32 are regions in the wiring30 that are disposed on the resin protrusion 20 (see FIG. 3C). Thecoupling sections 32 are regions of the wiring 30 used for electricalcoupling with conductive sections (e.g. the wiring pattern of the wiringsubstrate) of other electrical components. That is, the couplingsections 32 of the wiring 30 may be regions opposing (coming in contactwith) the wiring pattern 44 which will be described hereafter. Thewiring 30 is described herein as a single layer of wires. However, thewiring 30 may have multiple layers.

Examples of the material usable for the wiring 30 are, but not limitedto, Au, TiW, Cu, Ni, Pd, Al, Cr, Ti, W, NiV, Ag, and lead-free solder.

Method for Manufacturing Semiconductor Device 1

A method for manufacturing the semiconductor device 1 will now bedescribed. FIGS. 4A through 4C are diagrams to explain the method formanufacturing the semiconductor device 1 according to this embodiment.

The method for manufacturing the semiconductor device 1 includespreparing a semiconductor substrate 11 as shown in FIGS. 4A through 4C.FIG. 4A is a schematic diagram of the semiconductor substrate 11. FIG.4B is a partially enlarged diagram of a cut plane of the semiconductorsubstrate 11. FIG. 4C is a partially enlarged diagram of an upper planeof the semiconductor substrate 11. The semiconductor substrate 11 mayhave a shape of a wafer, as shown in FIG. 4A. Alternatively, asemiconductor substrate having a shape of a chip (a semiconductor chip)may be prepared, and then the following process may be conducted.Referring to FIGS. 4B and 4C, the semiconductor substrate 11 includesthe electrodes 12. The semiconductor substrate 11 may also include thepassivation film 16.

The method for manufacturing the semiconductor device 1 includes formingthe resin protrusion 20, with reference to FIGS. 5A through 5D. Theprocedure for forming the resin protrusion 20 is as follows.

First, with reference to FIG. 5A, a resin material 25 is provided abovethe semiconductor substrate 11. Then, referring to FIG. 5B, the resinmaterial 25 is partially removed and patterned. Thereafter, thepatterned resin material 25 is cured (e.g., thermally cured) to form theresin protrusion 20, with reference to FIGS. 5C and 5D. In thisembodiment, the resin protrusion 20 may be formed by melting and thencuring the resin material 25. In this case, the shape (the upper planeshape) of the resin protrusion 20 can be controlled by adjusting themelting and curing conditions of the resin material 25. For example, theresin material 25 is heated so as to melt only the surface but not thecore thereof (up to a half-melt state) and then cured, so that the uppersurface of the resin protrusion 20 is convexed. The shape of the resinprotrusion 20 can be controlled by adjusting the configuration,material, curing conditions of the resin material 25.

The method for manufacturing the semiconductor device 1 according tothis embodiment includes providing the wiring 30. The procedure ofproviding the wiring 30 will now be described. FIGS. 6A and 6B arediagrams to explain an exemplary process for forming the wiring 30.

First, with reference to FIGS. 6A and 6B, a metal layer 40 is providedabove the semiconductor substrate 11. The metal layer 40 may be providedcovering the electrodes 12 and the passivation film 16. The metal layer40 may be electrically coupled to the electrodes 12. The metal layer 40may be formed by sputtering, for example. An example of the material forthe metal layer 40 is, but not limited to, a material of low ductility(a brittle material) having a low electrical resistance value, such asAu.

The metal layer 40 is then patterned, thereby providing the wiring 30(see FIGS. 3A through 3C).

Then, through processes such as dicing the semiconductor substrate 11,testing, and removing a part of the exposed region of the resinprotrusion 20 exposed from the wiring 30, the semiconductor device 1 isprovided (see FIGS. 3A through 3C).

Method for Manufacturing Electronic Device

The method for manufacturing the liquid crystal device 100 as oneexample of the electronic device will now be described. FIGS. 7A through7D are diagrams to explain the method for manufacturing the liquidcrystal device 100 according to the present embodiment.

The method for manufacturing the liquid crystal device 100 according tothe embodiment includes preparing a wiring substrate 2. The structure ofthe wiring substrate 2 will now be described.

The wiring substrate 2 includes the base substrate 42 and the wiringpattern 44. The base substrate 42 (wiring substrate 2) of thisembodiment is composed of a part of the liquid crystal panel 110. Thebase substrate 42 may be a part of another electrooptical panel such asan electroluminescence panel. In such a case, the base substrate 42 maybe a ceramic substrate or a glass substrate, for example. Examples ofthe material for the wiring pattern 44 are, but not limited to, a metalfilm such as indium tin oxide (ITO), Cr, or Al, a metal compound film,and a compound of these films. The wiring pattern 44 may be electricallycoupled to electrodes for driving liquid crystal (e.g., a scanningelectrode, a signal electrode, and an opposite electrode).Alternatively, the wiring substrate 2 may be a resin substrate.

The method for manufacturing the liquid crystal device 100 according tothe embodiment includes preparing the semiconductor device 1. Thesemiconductor device 1 may be provided by the method as just describedor may have any of the structures as previously described.

The method for manufacturing the liquid crystal device 100 according tothe embodiment includes mounting the wiring substrate 2 above thesemiconductor device 1. Referring to FIGS. 7A through 7D, the process ofmounting the wiring substrate 2 above the semiconductor device 1 willnow be described.

First, referring to FIG. 7A, the semiconductor device 1 is disposedabove the wiring substrate 2. In this case, the semiconductor device 1is disposed such that the surface 15 of the semiconductor chip 10 facesthe wiring substrate 2. Also, the semiconductor device 1 and the wiringsubstrate 2 are aligned so that the electrical coupling sections 32(resin protrusion 20) of the semiconductor device 1 lie against(overlap) the wiring pattern 44 of the wiring substrate 2. The alignmentof the semiconductor device 1 and wiring substrate 2 may be performed,for example, by holding the semiconductor device 1 using a jig (abonding tool) (not shown). In this case, the semiconductor device 1 maybe held so that the surface 15 lies parallel to the wiring substrate 2.The jig may contain a heater for heating the semiconductor device 1. Byheating the semiconductor device 1, the coupling sections 32 are heated,and the coupling sections 32 and the wiring pattern 44 can beelectrically coupled successfully.

Referring to FIG. 7A, an adhesive material 52 may be provided in advancebetween the semiconductor device 1 and the wiring substrate 2. Theadhesive material 52 may be paste or film. The adhesive material 52 maybe an insulating material that does not contain conductive particles(i.e., nonconductive paste (NCP), nonconductive film (NCF)). Theadhesive material 52 may be provided, for example, on the wiringsubstrate 2.

Thereafter, referring to FIG. 7B, the semiconductor device 1 and thewiring substrate 2 are put close to each other so that the couplingsection 32 comes in contact and electrically coupled with the wiringpattern 44. In this process, with reference to FIG. 7C, thesemiconductor chip 10 and the wiring substrate 2 (base substrate 42)press down and elastically deform the resin protrusion 20. As the resinprotrusion 20 is pressed down, each coupling section 32 is also deformedand pressed against the wiring pattern 44. The shapes of the couplingsection 32 as pressed against the wiring pattern 44 will be described indetail hereafter. According to this description, however, because theelasticity of the resin protrusion 20 enables each coupling section 32to be pressed and attached to the wiring pattern 44, it is possible toproduce the liquid crystal display 100 with highly reliable electricalconnection. Also, in this process, the semiconductor device 1 and thewiring pattern 44 may be put close to each other while flowing theadhesive material 52.

Then, referring to FIG. 7D, the adhesive 50 is provided between thesemiconductor device 1 and the wiring substrate 2. The adhesive 50 isprovided upon curing of the adhesive material 52. The adhesive 50adheres (fixes) the semiconductor device 1 to the wiring substrate 2.The gap between the semiconductor chip 10 and the wiring substrate 2 maybe maintained by the adhesive 50. That is, with the adhesive 50, thestate of the elastic deformation of the resin protrusion 20 may bemaintained. For example, by providing the adhesive 50 after the resinprotrusion 20 has been elastically deformed, it is possible to maintainthe state of the elastic deformation of the resin protrusion 20. As aresult, it is possible to manufacture the liquid crystal display 100having highly reliable electrical connection between the electricalcoupling sections 32 and the wiring pattern 44. The material for theadhesive 50 is not particularly limited but may be formed using a resinmaterial, for example. Then, the adhesive material 52 may be the resinmaterial having thermosetting property.

Shapes of the electrical coupling sections 32 pressed against the wiringpattern 44

The shapes of the electrical coupling sections 32 as pressed against thewiring pattern 44 will now be described in detail with reference to FIG.8. FIG. 8 is a plan diagram of the pressed electrical coupling sections,as shown from P-P of FIG. 7D.

Referring to FIG. 8, the plurality of electrical coupling sections 32are provided while being pressed against the wiring pattern 44 in alongitudinal direction (X direction) of the convex-shaped resinprotrusion 20. The electrical coupling sections 32, deformed togetherwith the pressed and deformed resin protrusion 20, have predeterminedshapes and are in contact with the wiring pattern 44. FIG. 8 shows theshapes of the deformed coupling sections 32 in contact with the wiringpattern 44. The electrical coupling sections 32, namely from electricalcoupling sections 32-1 to electrical coupling sections 32-X, are alignedin opposing directions (toward end portions 20 a of the resin protrusion20 in the longitudinal direction) using a hypothetical center line Q1 ofthe resin protrusion 20 in the longitudinal direction (hereunderreferred to as “center line Q1”) as a reference. The coupling sections32 are curved in the directions of the end portions 20 a of the resinprotrusion 20 in the longitudinal direction. For example, with respectto the coupling sections 32-1, a length L2 from the center line Q1 to acenter (nearby a center line Q2) of the resin protrusion 20 in a widthdirection (Y direction) (hereunder referred to as “width-directioncenter”) is longer than a length L1 from the center line Q1 to ends ofthe resin protrusion 20 in the width direction (hereunder referred to as“width-direction ends”) 32 a, 32 b. Also, with respect to the couplingsections 32-X, a length L4 from the center line Q1 to thewidth-direction center is longer than a length L3 from the center lineQ1 to the width-direction ends 32 a, 32 b. Because of such a curvedshape, it is possible to increase the electrical contact area comparedto the straight-lined shape and to maintain more stable electricalcontact.

Described in this embodiment is the example in which the curvature isconvexed in the directions of the width-direction ends 32 a, 32 b.However, if the curvature is concaved in the directions of thewidth-direction ends 32 a, 32 b, the contact area also increases,producing the same effect.

Also, referring to FIGS. 9A through 9C, the shapes of the couplingsections 32 may be curved as mentioned, or bent, or may have a shapecombining the curved and bend shapes as long as the contact areaincreases.

Moreover, referring to FIG. 8, the coupling sections 32 are providedsuch that the amount of curvature increases gradually from the centerline Q1 to the end portions 20 a of the resin protrusion 20 in thelongitudinal direction (hereunder referred to as the “longitudinal endportions”). In other words, the difference between the length from thecenter line Q1 to the width-direction (Y-direction) center of the resinprotrusion 20 and the length from the center line Q1 to the ends 32 a,32 b increases gradually. That is, in the coupling sections 32, thedifference between the length from the center line Q1 to thewidth-direction center and the length from the center line Q1 to thewidth-direction ends 32 a, 32 b increases from the center line Q1 towardthe longitudinal end portions 20 a. To explain this with reference toFIG. 8, with respect to the coupling sections 32-1 near the center lineQ1, the difference between the length L2 from the center line Q1 to thewidth-direction center and the length L1 from the center line Q1 to thewidth-direction ends 32 a, 32 b is a difference in length L5. Incontrast, with respect to the coupling sections 32-X located near thelongitudinal end portions 20 a, the difference between the length L4from the center line Q1 to the width-direction center and the length L3from the center line Q1 to the width-direction ends 32 a, 32 b is adifference in length L6.

Thus, the difference in length L6 is greater than the difference inlength L5 (L6>L5), and the difference in length increases from thecenter line Q1 to the longitudinal end portions 20 a. In other words,the curvature becomes gradually larger from the center line Q1 to thelongitudinal end portions 20 a. As the curvature becomes larger, thecontact areas of the coupling sections 32 increase gradually from thecenter line Q1 to the longitudinal end portions 20 a. Here, because theconvex-shaped resin protrusion 20 is made of resin having a largeexpansion coefficient, the resin protrusion 20 experiences greaterthermal expansion due to environmental temperature changes as comparedto the base substrate 42. Thus, the expansion amount at the longitudinalend portions of the resin protrusion 20 is maximized. On the contrary,because the contact area of the coupling sections 32 increases graduallyfrom the center line Q1 to the longitudinal end portions 20 a, it ispossible to maintain the electrical contact even if the expansion amountat the longitudinal end portions of the resin protrusion 20 increases.Therefore, it is possible to provide the electrooptical device (liquidcrystal display 100) capable of withstanding temperature changes andmaintaining a stable electrical contact.

As described, the thermal expansion amount of the convex-shaped resinprotrusion 20 is at its maximum at the longitudinal end portions 20 a.Therefore, instead of making the amount of curvature of the couplingsections 32 to increase gradually from the center line Q1 to thelongitudinal end portions 20 a, the same effect can be produced bymaking the amount of curvature larger near the longitudinal end portions20 a than near the center line Q1.

Additionally, it is possible to provide an electronic apparatus whichcontains the described electronic device and a control section having afunction to at least operate components including this electronicdevice. FIG. 10 shows a notebook type personal computer 2000 as anexample of the electronic apparatus, and FIG. 11 shows a mobile phone3000 as another example of the electronic apparatus. The notebook typepersonal computer 2000 or the mobile phone 3000 is equipped with theliquid crystal device as an example of the electronic device. Thecontrol section (now shown) may be a central processing unit (CPU), forexample.

According to the structure as described, it is possible to maintain andprevent deterioration of the good electrical contact state of the wiringsubstrate, resin protrusion, and the like that constitute the electronicdevice, even if their thermal expansion varies due to temperaturechanges. It is therefore possible to provide the electronic devicecapable of maintaining more stable electric contact.

1. An electronic device, comprising: a semiconductor device including: asemiconductor chip having an electrode; a convex-shaped resin protrusionprovided on a surface of the semiconductor chip, the surface having theelectrode; and wiring having a plurality of electrical coupling sectionswhich are aligned on the resin protrusion and electrically coupled tothe electrode; and a wiring substrate having a wiring pattern, wherein:the semiconductor device is mounted to the wiring substrate so that theelectrical coupling sections and the wiring pattern are brought intocontact and electrically coupled with each other; and the plurality ofelectrical coupling sections brought into contact with the wiringpattern include curved or bent shapes projecting in a longitudinaldirection of the resin protrusion.
 2. The electronic device according toclaim 1, wherein: the plurality of electrical coupling sections broughtinto contact with the wiring pattern are provided such that a firstlength from an end thereof in a width direction of the resin protrusionto a hypothetical center line of the resin protrusion in thelongitudinal direction is longer than a second length from a centerthereof in the width direction of the resin protrusion to thehypothetical center line.
 3. The electronic device according to claim 1,wherein: the plurality of electrical coupling sections brought intocontact with the wiring pattern are provided such that a first lengthfrom an end thereof in a width direction of the resin protrusion to ahypothetical center line of the resin protrusion in the longitudinaldirection is shorter than a second length from a center thereof in thewidth direction of the resin protrusion to the hypothetical center line.4. The electronic device according to claim 3, wherein: the plurality ofelectrical coupling sections brought into contact with the wiringpattern are provided such that a difference between the first lengthfrom the end thereof in the width direction of the resin protrusion tothe hypothetical center line in the longitudinal direction and thesecond length from the center thereof in the width direction of theresin protrusion to the hypothetical center line is larger at both endportions of the resin protrusion in the longitudinal direction than at acentral portion of the resin protrusion in the longitudinal direction.5. The electronic device according to claim 4, wherein: the plurality ofelectrical coupling sections brought into contact with the wiringpattern are provided such that, the difference between the first lengthfrom the end thereof in the width direction of the resin protrusion tothe hypothetical center line of the resin protrusion in the longitudinaldirection and the second length from the center thereof in the widthdirection of the resin protrusion to the hypothetical center lineincreases gradually from the central portion of the resin protrusion inthe longitudinal direction toward the both end portions of the resinprotrusion in the longitudinal direction.
 6. An electronic apparatus,comprising: the electronic device according to claim 1; and a controlsection having a function to at least operate a component including theelectronic device.